Giovanni Mascellani (@giomasce) commented about tests/hlsl-is-front-face.shader_test:
- } m;
 +};
+struct output +{
- struct
 - {
 float4 color : sv_target;- } m;
 +};
+struct output main(struct input i, bool face : sv_isfrontface) +{
- struct output o;
 - o.m.color = i.m.texcoord;
 - if (face) o.m.color += float4(1.0, 1.0, 1.0, 1.0);
 
IMHO let's avoid this style even in tests.